1. Field of the Invention
The present invention relates to control systems for copying machines, and particularly to a control system for copying machines in which data for controlling the copying machines are transmitted to a centralized control unit on the center side.
2. Description of the Related Art
A system for controlling a plurality of copying machines is disclosed in U.S. Pat. No. 4,583,834. In this disclosed system, various information of copying machines such as the total number of copies, troubles, remaining quantities of copy sheets and toner are transmitted to a computer. The computer processes the transmitted information and feeds back instructions to the copying machines.
According to such a system, a plurality of copying machines supplied to users are connected to a centralized control unit through a communication network such as telephone lines for remote control of the copying machines. The centralized control unit is provided at a control base, and the controlling party receives with the centralized control unit the information transmitted from respective copying machines. Then, controlling works such as the issue of bills corresponding to the number of copies and dispatch of servicemen corresponding to the troubles are made.
Since general copying machines do not have functions of communicating with a centralized control unit through a communication network, a data terminal is attached to a copying machine for communication when configuring said system. This data terminal collects various information from the copying machine and communicate with the centralized control unit on the basis of the collected information.
When a single user has a plurality of copying machines, a data terminal is provided for each copying machine. However, in consideration of cost and usage efficiency of the line, it is not reasonable to provide a communication line for communication with a centralized control unit for every data terminal.